Penicillium sanguifluum (Penicillium section Citrina) as a source of dehydrocurvularin and its antifungal and antibacterial properties.

Antimicrobial resistance has a negative impact on people's health and the economy. New resistance mechanisms are emerging, making the treatment of infections very challenging. Fungi are well known for their production of secondary metabolites during active cell growth. In this study, a strain of Penicillium sanguifluum (111-12) was isolated from Manitoba soil and investigated for antimicrobial properties of fungal secondary metabolites against pathogenic bacteria, and two fungal plant pathogens that are known for causing Dutch elm diseases and chestnut blight disease. Penicillium sanguifluum (111-12) produced dehydrocurvularin (C1) and 11-hydroxycurvularin (C2). C1 and C2 were examined for their antimicrobial properties and these compounds were combined with various antibiotics to evaluate their potentiation (adjuvant) properties. Promising results were obtained for C1 that decreased the minimum inhibitory concentrations of cefepime, ceftazidime, tobramycin, and amikacin against a clinical multidrug resistant strain of Pseudomonas aeruginosa (PA82). In addition, C1 and C2 showed no impact on the Galleria mellonella model regarding toxicity.